磷钼杂多酸季铵盐催化氧化合成苯甲酸

采用四丁基溴化铵和磷钼酸反应合成了一系列Keggin型磷钼酸季铵盐催化剂,傅立叶红外光谱分析表明,所制备的催化剂具有典型的杂多阴离子结构.将其应用于冰乙酸作溶剂、30%过氧化氢作氧化剂催化氧化苯甲醛制苯甲酸的反应过程中,详细考察了反应条件对反应的影响.结果表明,催化剂中各组分在双氧水作用下催化活性较高,任一组分单独作用时催化活性较低,只有当催化剂中季铵盐与磷钼酸配比合适时,催化效果才会最优,其中(C4H9)4N]H2PMo12O40的催化活性最优.在最佳合成条件下,即苯甲醛20 mmol、30%双氧水60 mmol、催化剂0.07 mmol、冰乙酸8 mL、反应温度75℃、反应时间6 h,苯甲酸收率达87.82%,且催化剂重复使用情况良好.

Synthesis of Benzoic Acid Catalyzed by Quaternary Ammonium Heteropolyphosphamolybdenum

The Keggin-type heteropolyacid of phase transfer catalysts had been synthesized with tetra-n-butylammonium bromide and phosphamolybdenum acid,and were characterized by infrared ray spectroscopy.The data indicated that they had the heteropolyanions structure.The oxidation of benzaldehyde to benzoic acid used ethanoic acid as medium and 30% hydrogen peroxide as oxidant under the mild condition.The effects of different conditions were investigated.It was found that the component of the catalyst had high activi...